An optical path network is known that transmits wavelength division multiplexing (WDM) light including a plurality of for example, M, wavelength groups each formed by multiplexing lights of N multiple wavelengths respectively corresponding to a plurality of, for example, N, wavelength channels (wave channels or light paths) acquired by dividing a predetermined communication wavelength band by, for example, 100 GHz, via a plurality of (K) optical fibers in parallel. Anode switching a route on the basis of a wavelength group or switching a route on the basis of a wavelength in such an optical path network uses an optical matrix switching apparatus that is a relatively large-scale multi-input multi-output optical switching apparatus for extracting and dropping an optical signal of a predetermined wavelength from KMN wavelength channels included in the wavelength groups transmitted through the K optical fibers to an electric layer EL performing signal conversion between an electric signal and a wavelength-based optical signal by using a router etc., for the signal for which the node is the destination, or for adding an optical signal converted from an electric signal by a predetermined router to the wavelength division multiplexing light in a predetermined optical fiber. Patent Document 1 described an example thereof.
The node of the optical path network desirably has a function enabling the dropping of any wavelength channel in wavelength division multiplexing light in any input fiber and enabling an assignment of a wavelength channel added from the node to wavelength division multiplexing light of an arbitrary output fiber between a wavelength level transmitted through optical paths and an electric level at the time of an optical signal termination process, and a function having no mutual effect between a wavelength and connection to an optical transceiver, i.e., a colorless function, a directionless function, and a contentionless function.